The present invention relates to a method and apparatus for terminating electrical cables and, more particularly, to a grounding strap for terminating the outer shielding conductor of an electrical cable, to a method of mounting a grounding strap to a cable, and to a method of manufacturing grounding straps.
Shielded electrical cables having one or a plurality of signal-carrying center conductors surrounded by one or more tubular-shaped, braided outer conductors are used in applications wherein shielding is desired to reduce electromagnetic interference of the signals transmitted by the cable. Shielded cables are often used to transmit signals from remote locations to processing circuitry located within a housing or other enclosure; and, in such applications, it is desirable to dissipate the noise carried on the outer shielding conductor the cable prior to entrance of the cable into the housing and into the circuitry, as any noise present on the outer conductor can interfere with the electronics in the circuitry. Power cables also frequently include an outer conductor coaxially encompassing other conductors of the cable to provide a protective ground.
Various devices have been used to ground the outer shielding conductor of a cable. Many prior devices were not satisfactory because it was necessary to cut through the cable or to otherwise prepare the cable for receipt of the grounding structure.
In one known grounding device, the braided outer conductor of a cable was grounded by electrically conductive contact tips or prongs extended through the outer jacket of the cable into contact with the outer conductor. The prongs were mounted on or affixed to an external grounding structure to provide a grounding path from the prongs to external ground to dissipate noise carried by the outer conductor.
In another known grounding device, a pair of contact prongs is mounted on a deformable support plate so that the prongs are embedded within the cable by pressing the plate and cable together. The support plate bends to conform to the curvature of the cable, causing the embedded tips of the prongs to turn toward one another to grab and retain the braided conductor therebetween.
Such known devices have not been fully satisfactory. In such devices, only a few prongs were inserted into the cable, and the inserted prongs were disposed in such a manner that the outer conductor was not reliably grounded. In many such devices also, it was necessary to manufacture the grounding structure in a variety of sizes to terminate cables of different diameter.